Process of making prelubricated paper

ABSTRACT

PAPER, SUITABLE FOR ANY INTERMEDIATE OR END USE APPLICATION WHICH REQUIRES THE CUTTING, PUNCHING OR TRIMMING OF THE PAPER, IS PRODUCED BY AN IMPROVED PROCESS WHICH INCLUDES SIZING THE PAPER MADE OF CHEMICAL WOOD PULP AT THE SIZE PRESS WITH AN OIL-IN-WATER EMULSION CONTAINING STARCH, WHEREBY SMALL QUANTITIES OF LUBRICATING OIL CAN BE INCORPORATED UNIFORMLY INTO THE PAPER. THE PAPER THUS TREATED CONTAINS AN EVENLY DISTRIBUTED AMOUNT OF OIL RANGING FROM ABOUT 0.2 POUND TO 1.5 POUNDS PER REAM OF PAPER. THE PRODUCT DOES NOT SUFFER FROM OIL ODOR OR OIL BLEEDING AND HAS GREATLY IMPROVED OPACITY OVER OTHER OILED PAPERS HERETOFORE KNOWN IN THE ART.

United States Patent 3,702,801 PROCESS OF MAKING PRELUBRICATED PAPER Michael L. De Matte, Columbia, Md., assignor to Westvaco Corporation, New York, N.Y. Continuation-impart of abandoned application Ser. No. 63,599, Aug. 13, 1970. This application 'July 2, 1971, Ser. No. 159,505

Int. Cl. D21h 3/04, 3/10 US. Cl. 162-173 4 Claims ABSTRACT OF THE DISCLOSURE Paper, suitable for any intermediate or end use applica tion which requires the cutting, punching or trimming of the paper, is produced by an improved process which includes sizing the paper made of chemical wood pulp at the size press with an oil-inwater emulsion containing starch, whereby small quantities of lubricating oil can be incorporated uniformly into the paper. The paper thus treated contains an evenly distributed amount of oil ranging from about 0.2 pound to 1.5 pounds per ream of paper. The product does not suffer from oil odor or oil bleeding and has greatly improved opacity over other oiled papers heretofore known in the art.

BACKGROUND OF THE INVENTION This application is a continuation-in-part of patent application Ser. No. 63,599, filed Aug. 13, 1970, and now abandoned.

The paper produced by the present invention is intended for use in any operation which requires that the paper be cut, punched or trimmed. Papers of all weights and grades must be subjected to different finishing operations in preparing the paper for its ultimate end use. Among these operations are cutting, punching and trimming operations. Moreover, some kinds of paper must be specifically designed for their own particular end use which may in fact be a cutting or punching operation. Accordingly, applicant has, with the present invention, developed a process for treating paper which renders the paper more suitable than previously known papers for any finishing operation or end use which requires cutting, punching or trimming of the paper.

Generally, the above-mentioned finishing operations or end use functions of the paper are performed with knives, both rotating and fixed, or with dies and punches, operating either in a punch type die-press or in a rotary press. In each instance, the paper, or several blanks of the paper must be cut or punched smoothly and clearly without tearing or splitting the paper. Furthermore, for efficient and economical operation, the paper must exhibit good release characteristics fromthe die or punch type presses, and, the anti-static properties of the paper must be superior to insure runnability. Finally, however, one of the most important factors in developing a paper suitable for the cutting, punching or trimming operations hereinbefore mentioned, is the ability of the paper to perform in such operations satisfactorily without causing undue wear on the element which effects the particular operation to the paper.

In order to avoid excessive wear of the dies, punches and knives often used in performing the above operations, the paper is often treated with a lubricating oil. Conventionally, the oil is applied to the paper by the converter by immersing the paper in oil or more often by applying the oil to the paper by an applicator roll. Different kinds of paper absorb the oil in different amounts depending upon the method of application and kind of paper treated. Conventionally oiled paper may contain from to oil by weight and usually contains from 15 to 22% oil by 3,702,801 Patented Nov. 14, 1972 weight. It is difiicult to apply oil to paper at a level below about 10%, the minimum. amount which can be applied uniformly by applicator roll. While oiling the paper prolongs the life of the dies, punches and knives in the finishing and ultimate use applications, and, may even lengthen the shelf life of the paper, oiled paper has had serious disadvantages over unoiled paper. First, the oiling process has been a separate process which in the past has been performed by the converter. Applying oil to paper by applicator roll or by dipping has been a diffiacult and inefficient process. Secondly, with the amounts of oil needed to achieve uniform distribution of oil, oil odor and bleeding have often been problems with oiled paper because of the excessive amounts of oil employed. To date, there has been no satisfactory way to apply less oil in a uniform manner. Furthermore, oiling lowers the opacity of the paper and this can cause serious problems when the paper is used as code paper, for instance, which requires interpretation with an optical reader. Less opacity in the no-hole areas of code paper tape increases the light transmission therethrough and can lead to a misreading of the coded data on the encoded paper tape.

Moreover, when the paper is utilized for envelope or card stock, or, for labels which must be printed, the amount of oil applied to the paper cannot be excessive or the brightness and pick resistance of the paper become unacceptable. These factors are particularly important when coated papers are treated with oil to improve their handling characteristics. Initially, the addition of a pigmented coating to the paper will in itself drastically increase the wear on cutting knives and dies and on the punches used in typical finishing and end use applications. Moreover, an imbalance between the quantity of binder, the quantity of pigment, and the quantity of oil results in a poor coating composition for letterpress or web offset printing purposes. Thus the incorporation of an oil treatment in a coating composition applied to the paper, as taught by some of the prior art processes, is clearly undesirable as regards printability, and, as regards satisfying the requirements of applicants invention. Accordingly, while the benefits of oiled paper, both coated and uncoated, are desirable, the problems attendant with the previous methods for applying the oil have been considerable.

One particular kind of paper which has an end use that requires a punching operation which produces severe wear to the punches is code paper. Code paper is paper designed to be converted into perforator tape, the punched tape used in teletype machines, computers, automatic type setting systems, and various data processing systems. In general, code paper is made entirely from chemical wood pulp which is free of fillers and abrasive particles. The paper may be unoiled or oiled by the converter for better lubricating properties, as discussed below. The paper is converted into tapes by slitting it into widths ranging from about one-half inch to three inches, the most frequently used tape widths being in the order of 0.685, 0.875, and 1.0 inch.

In use, letters, numbers, punctuation and certain machine-function instructions are represented on the code paper tape by a code consisting of holes punched across the tape. The small piece of paper which is removed by the punch is called a chad. The holes are placed in the tape by a tape punch or perforator which is usually an electromechanical device which uses pins to punch data on the tape. Some punches are activated by a keyboard, some by electrical impulses from. another machine such as a computer or data transmission device, and others are activated by both means. The codes placed on the tape employ various hole/no-hole combinations in channels which may range in number from five to eight. In addition to the code holes across the tape, the tape usually carries feed holes so that in a five-channel code, for example, a fully punched tape would have three code holes, a feed hole, and two or more code holes centered on a line perpendicular to the lengthwise direction of the tape.

Coded tapes are read in tape readers which sense the holes and translate them into electrical impulses. The tape readers are either mechanical or optical. Mechanical readers have feelers for sensing the hole/no-hole combinations. Optical readers use light which passes through the code holes but is hopefully opaqued out in the nohole areas.

In order to avoid excessive wear of the punches, code paper has been subjected to lubricating treatments particularly as taught by U.S. Letters Patent No. 3,535,155. Accordingly, it is an object of this invention to treat code paper with the novel process described herein for achieving the desired improved punch wear without encountering the undesired effects of the prior known treatments.

In addition, it has also been found that uncoated paper, for use as envelope basestock for instance, can also achieve improved runnability when treated with the novel process disclosed herein. Typically, envelope basestock is sheeted in a conventional sheeting operation which requires passing the paper web through a sheeter, the cut sheets are then stacked on skids, and, then taken to a second cutting station where the envelope panels are cut from the paper. Finally, the partially formed envelopes are then transferred to another cutter where the remaining cut-outs are made for coupons or window areas. Each of these cutting steps requires the use of a knife, die or punching type mechanism which is subject to severe wear when the particular cuts are performed. Thus to prolong the life of the cutting instruments used in the manufacture of envelopes from uncoated envelope basestock, the basestock can be treated with the novel process described and claimed herein. Therefore, it is another object of this invention to produce an improved self-lubricating envelope paper basestock, by applying the novel oil-in-water emulsion claimed, to the paper, to improve the runnability of the paper and achieve prolonged die life.

Moreover, other and different products produced while practicing the novel process described herein have also been discovered. As mentioned before, the application of the novel sizepress treatment disclosed, to different grades of papers both coated and uncoated, is beneficial from the point of knife, die and punching equipment wear, when the paper is subjected to any cutting, punching or trimming operation. Accordingly, it was found that label paper, including pressure sensitive, self-facing label paper, and, conventional coated-one-side (ClS) label paper each performed with improved runnability on the die press with drastically reduced die wear, after treatment by applicants process.

Generally, self-facing label paper is uncoated, and, it is cut into labels of the prescribed dimensions as the last step in its manufacture. For this purpose, a sandwich construction is prepared which includes, reading from top to bottom, (1) the label or facing paper, (2) a layer of pressure sensitive adhesive, (3) a layer of silicone type release coating, and (4) the release paper itself. Webs of this sandwich construction are then conducted to a cutting section, or, die press, (either rotary or punch-type) where the cutting elements of the die penetrate the first or facing (label) layer of the sandwich construction and the adhesive layer, while only kissing the release paper. Thus the labels are out only from the paper itself leaving the release coating and release sheet intact. For use, the labels are simply peeled off of the release paper, with the pressure sensitive adhesive adhering to the labels due to the presence of the release coating. In this operation, the die wear in the label forming operation is both considerable and a serious matter. Furthermore, when the label paper itself for pressure sensitive labels is coated, or when conventional coated label papers, without the pressure sensitive adhesive, are cut into labels for a particular end use, the effects of die wear are more troublesome simply because of the presence of the pigmented coating. Hence, yet another object of this invention is to increase the runnability and die life of cutting elements when papers, both coated and uncoated are cut, punched or trimmed, by treating the papers with the novel process disclosed herein which papers may then be used as pressure sensitive or conventional label papers.

Consequently, the papers produced while practicing the herein disclosed process are intended to be used, in either an intermediate use or as an end use, in any operation involving the cutting, punching or trimming of the paper.

SUMMARY OF THE INVENTION The present invention concerns oiled paper which does not suffer from oil odor and bleeding as in the past, and which is self-lubricating to increase the life of any cutting, punching or trimming element that operates on the paper. The paper is produced in one basic operation and eliminates the need for a separate oiling procedure by the converter. The new prelubricated paper has greatly improved opacity over oiled papers known in the past. Surprisingly, it has been found that the same degree of lubrication as that found in known oiled papers containing as much as 25% oil by weight, can be achieved by use of much less oil if the oil is applied to the paper made from chemical wood pulp as part of a starch sizing while the paper is being manufactured on the papermachine. It has been found that as little oil as 0.2 pound per ream of paper, applied according to the present invention, provides the final oiled paper with as much lubricity as paper treated in a separate converting operation to contain 15 pounds per ream of oil. Because the oil level is low in the code paper when applied according to the present invention, the final product has a much higher opacity than previously known oiled papers. One problem in the past has been that one could not pigment oiled paper to improve opacity because the abrasive pigment would damage the cutting, punching and trimming elements when the paper was used. Yet while oiled paper has been desirable to lubricate the knives, punches and trimmers, and, prolong the shelf life of the paper, oiling has seriously affected the opacity of the paper. By the present invention, opacity of the oiled paper is maintained at no expense of lubricity.

According to the present invention, a dispersion of starch in water is first prepared. Under agitation, an emulsifier is added to the aqueous starch dispersion and then a lubricating oil is slowly added to produce an oil-inwater emulsion. The resultant oil-in-water emulsion may be applied to the base paper web by any suitable means such as dipping, spraying, and brushing, but preferably is applied by means of a conventional or gateroll size press on a papermachine. The paper is impregnated with the emulsion at the size press and is subsequently dried to a moisture content of about 4 to 8%. The resultant prelubricated paper is then suitable for use in any cutting, punching or trimming operation without the necessity of any further oil treatment of the paper. Furthermore, the oil is uniformly contained within and on the paper in an amount which heretofore could not be applied uniformly to paper in a separate oiling treatment.

The invention is not limited to the use of a particular type of starch in the sizing. Pearl, acid modified, cationic, oxidized, and ethylated starches can be used in the sizing, with the preferred being pearl corn starch. The amount of starch in the oil-in-water emulsion can be varied from about 1.5% to 15% by weight, with the preferred being about 5 to 7% by weight. Above about 15% starch by weight, the oil-in-water emulsion becomes too viscous for easy handling. Below about 1.5% starch by weight, the emulsion becomes unstable and is not suitable for size press application.

The oil used in the present invention can be any of the known liquid lubricating oils, including motor oils, paraffin-based oils, and mineral oils. The viscosity of the oil component can be quite variable and may for example range from a Brookfield of about 27 centipoises (No. 1 spindle, 20 r.p.m.) to about 870 centipoises (No. 2 spindle, 20 rpm.) when measured at about 25 C. The amount of oil in the emulsion is quite small, ranging from about 1% to and preferably from about 3% to 5%, by weight of the total emulsion including starch, water, emulsifier and oil. At these concentrations, the amount of oil picked up by the paper at the size press has ranged from about 0.2 pound to 1.5 pounds per ream, with the pre ferred pickup being in the range of about 0.5 to 1.1 pounds per ream of paper (500 sheets, 25 x 38 inches). Obviously, the amount of oil used can be above that stated, but oil odor and oil bleeding may occur as well as losses in opacity when increased amounts of oil are used. As previously stated, oil applied in accordance with the present invention is uniformly distributed throughout the paper even though it is present in a very limited quantity.

As stated, a lubricating oil forms the internal phase of the oil-in-water emulsion when the oil is emulsified or dispersed in the aqueous starch dispersion. The internal oil phase is present in the external phase of the aqueous starch dispersion as droplets, such as is true for oil-in-water emulsions. Any suitable emulsifier can be used in sufficient quantity to effect an oil-in-water emulsion. Preferred, but not limited thereto, are such emulsifiers known commercially as Tween 80, a polyoxyethylene sorbitan monooleate, and Tergitol-NP27, a nonyl phenylethylene glycol ether. The emulsifier preferably is added to the aqueous starch dispersion before the oil is added thereto, but the emulsifier optionally may be added to the dispersion of starch simultaneously with the addition of the lubricating oil, or the lubricating oil may be mixed with the emulsifier prior to being added to the starch dispersion.

The base paper used for purposes of the present invention has been referred to as paper made wholly from chemical wood pulp. As those skilled in the art will readily appreciate, chemical wood pulp is obtained by digestion of wood with various cooking solutions and includes pulp prepared by the known sulfate (or kraft process), sulfite, and neutral sulfite semichemical processes. The chemical wood pulp used herein is preferably bleached to produce a white pulp.

One surprising feature of the code paper produced by the improved process of this invention is its low coefiicient of friction as compared to paper oiled conventionally by the converter and containing many times the amount of oil. The lower coefficient of friction is a benefit because tapes produced from the code paper made by the present process have good antistatic properties. Because static charges do not tend to build during the encoding operation, chads punched from the tapes do not tend to gather and hamper the runnability of the tapes or the operation of the punches.

In addition, the envelope basestock produced by the improved process of this invention was found to have improved runnability in both the conventional die press and the programmed die press. The die operators found that the paper, as treated with the disclosed process was smoother and more slippery, yet higher lifts (or stacks of blanks) could be cut in the die presses with even worn dies, and there was substantially no top to bottom variation in the cuts made. That is, with other envelope basestock, the die operators found that with nominally high lifts, and, when using new, sharp dies, the paper tended to move or shift in the lift as the die passed through the stack. This movement generally caused a variation in the dimensional size of the envelope blank cut at the bottom of the lift as compared with the blank at the top of the lift. With the prelubricated paper produced while practicing applicants process, the die made a clean cut with substantially no top to bottom variation in cut. This factor was attributed directly to the lower coeflicient of friction of the treated paper as compared With the coefficient of friction of the control. Moreover, the same prelubricated paper printed satisfactorily with, (1) oil base ink, (2) aniline ink, and (3) in an aniline printer on a folding machine.

In summary, based on actual production tests of the prelubricated paper produced by the present invention, the following improvements were noted: (1) longer die wear, (2) higher lifts cut, (3) ease of cutting and release from the die, (4) substantially no top to bottom variation in cutting, (5) better quality cutting, i.e., elimination of pressure points, pronounced burr, and no chipping, cracking or splitting, (6) considerably fewer damaged or sprung dies, (7) a somewhat diminished noise level on hard to cut paper, and (8) better panel cutting on window forming machines.

With the application of the herein disclosed novel process to label paper both coated and uncoated, and, particularly to self facing pressure sensitive label papers, reduced die wear was the most noticeable improvement found with the prelubricated paper. Because of the extremely close tolerances required in the cutting area of the cutter used in manufacturing self facing pressure sensitive label paper, die wear Was always a problem. However with applicants prelubricated paper, die wear was substantially reduced.

DETAILED DESCRIPTION The invention will be described in greater detail with the aid of the following examples.

Example 1 An aqueous dispersion of pearl starch was prepared by cooking the starch as an aqueous slurry of about 5 to 10% solids in a continuous jet cooker at a temperature of about 320 F., pressure of about p.s.i., for about 35 minutes, and then diluting the resultant cooked starch with sufficient water to produce 1000 gallons of a 6% by weight aqueous dispersion of starch. Under agitation, 1 gallon of Tergitol-NP27 emulsifing agent was added to the starch dispersion. Then with continuous agitation, 40 gallons of Faxam-40 lubricating oil (one of a line of lubricating oils produced by Humble Oil & Refining Company), having a Brookfield viscosity of about 40 centipoises (No. l spindle, 20 rpm, room temperature), were added to the aqueous starch dispersion over a period of about two hours, to produce an oil-in-water emulsion. The amount of oil in the resultant emulsion was about 4% by weight. The viscosity of the milky-white size press emulsion was about centipoises Brookfield (No. 2 spindle, 60 rpm, 106 F.). The emulsion was stirred for about one-half hour prior to screening and pumping to a size press 1w cated between two drier sections on a commercial papermaking machine.

The paper being made on the papermachine was comprised of about 80% neutral sulfite semichemical pulp and about 20% sulfate pulp. The paper had a basis weight of about 54 pounds per ream. The emulsion was applied to the paper by a conventional vertically-oriented size press, with the web of paper entering the nip of the press in straight-through fashion. The emulsion was placed on the top of the traveling web by means of shower pipes located immediately before the nip formed by the press rolls. The underside of the web was likewise sized with the oil-in-water emulsion by applying the emulsion to the lower press roll which delivered the emulsion to the paper web as it passed into the nip formed by the upper and lower press rolls. After the traveling web was impregmated with the emulsion at the size press, the web was dried to a moisture content of about 6%. An analysis of the paper so-produced showed that it contained about 1.1 pounds of oil per ream of treated paper. The oil, which represented only about 1.9%. by weight of the paper, was uniformly distributed throughout the paper. The opacity Size press emulsions were prepared as in EXample l, with the amounts of oil being present in the emulsions by weight percent as shown below. The emulsions were applied by size press to paper made from chemical pulp, with the amount of oil impregnated into the paper as set forth below. After the sized paper was dried, opacity measurements were made.

Percent oil Oil in paper B & Example in sizing (lb/ream) opacity Lubriclty 2 (control) 0 73.3 19 3 3 16 72. 7 28 6 21 71. 7 31 9 28 71. 0 31 It can be seen that the opacity of the paper treated by the present invention was only slightly different from that of Example 2 which was sized with a starch sizing containing no oil.

Part of the paper from Example 2 was oiled by conventional means employed heretofore to produce oiled code paper. At minimum applications, suflicient to provide a uniformly oiled product, the surface treatment with oil produced a paper containing about 8 pounds per ream oil. The B & L opacity of the conventional product was only about 51.7, a drastic opacity reduction over the starch-sized paper and the paper treated according to the present invention in Examples 3-5.

Examples 6-9 Percent Static cooil in elfielent Example sizing of friction Lubricity 6 (control) O 0. 40 19 7 3 0. 36 27 6 0. 34 28 9 9 0. 34 28 The oil pickup in the paper was again in the range of that shown in Examples 2-5, i.e., from about 0.16 to about 0.40 pound of oil per ream of paper, going from those emulsions containing the smaller quantities of oil to those containing higher quantities.

Paper from Example 6, which had been sized with a 6% ethylated starch sizing and dried, was treated conventionally with the Unico oil. The paper contained about 15 pounds of oil per ream of paper. The lubricity of the oiled paper was about 29 and the coefficient of friction was 0.40. It can be seen that the papers treated according to the present process had lubricities about the same as the conventionally oiled paper containing much more oil, and had lower coefficients of friction than either unoiled paper or paper oiled in the conventional manner.

Examples 10-11 Further size press emulsions were prepared as in Example 1 with a pearl starch solution and Faxam-40 lubricating oil, with the amounts of oil being present in the emulsions by weight percent as shown below. The emulsions were applied by size press to envelope basestock paper made from chemical pulp, with the amount of oil impregnated into the paper as set forth below.

Oil in Static Percent 011 paper coefficient Example in sizing (lb/ream) of friction Lubrlcity 10 (control) 0 0 O. 44 18 11 4 1. 03 0. 31 30 Each paper, produced as a control with no oil in Example 10, and, as the prelubricated paper of Example 11, was tested as a potential paper for envelope basestock. The paper of Example 11 was then utilized in a trial to make envelope paper to observe the runnability and die wear as mentioned hereinbefore. The substantial improvement noted for both factors was attributed directly to the higher lubricity and lower coelficient of friction of the prelubricated basestock.

Examples 12-13 In these examples, a basestock of 61 pound basis weight was prepared for self facing label paper substantially as described in Example 1. Part of the paper thus produced was used as a control, with no oil treatment, and part was treated with the size press emulsion as prepared in Example 1 using a 5% pearl starch solution and Faxam- 40 lubricating oil. The amount of oil present in the emulsion by weight percent is shown below and the amount of oil impregnated into the paper is also shown.

Percent Oil in oil in paper Example sizing (lb. /ream) Lubriclty 12 (control) 0 0 18 13 4 0. 84 26 Examples 14-16 To test the general utility of the disclosed process on both coated and uncoated basestock, a 50 basis weight paper of low moisture content (less than 2%), made from 60% pine and 40% hardwood was prepared. The uncoated paper was then surface sized with a size press emulsion substantially as prepared in Example 1. The size press emulsion included a 5% pearl starch emulsion, with one part per thousand Tergitol NP-27. To this dispersion, there was added an amount of Faxam-40 lubricating oil and the mixture was agitated with a lightening mixer to form a stable oil-in-water emulsion. Lubricity tests were then performed as before on both the surface sized paper and on the control (Example 14), with the following results.

Percent 011 in oil in paper Example sizing (lb .lream) Lubrlclty 14 (control) 0 O 27 15 6 0. 38 41 16 12 0.80 41 ing a finishing or end use operation on the paper thus produced.

Examples 17-19 Percent Oil in oil in paper Example sizing (lb./ream) Lubn'city 17 (control) 0 21 18 6 0. 28 28 19 12 0.39 34 The control with coating showed a poorer lubricity than the uncoated basestock (Example 14), and, the amount of oil impregnated in the paper was less at the same two levels of oil addition used in Examples 15 and 16. However, the lubricity of the coated paper did increase with applications of oil higher than the 6% level which was noted as yielding the maximum elfectiveness in Example 15. Thus it can be seen that even coated paper treated with applicants novel process should show the same improved die wear and runnability that was found in actual tests on code paper, envelope stock and self-facing label paper.

Presently, there is no industry-wide standard for measuring lubricity, but the Stanley Knife test is known for use in such determinations. A number of sheets in pad form (35-50 sheets, for example) are subjected to a series of ten cuts, and the final sheet penetrated by at least three of the ten cuts is taken as a measure of the lubricity of the sheets. Determinations of lubricity according to the Stanley Knife test have correlated well with actual field results on the wear of punches used to encode paper.

From the above examples, it can be seen that an improved process for making oiled paper has been disclosed. By sizing paper made of chemical pulp with an oil-in-water emulsion containing starch in sufiicient quantity to render the emulsion stable under sizing conditions, an oiled paper can be produced which has equal lubricity, better antistatic properties, and significantly better opacity, and which does not suffer from oil odor or oil bleeding, as compared to conventionally oiled papers. By the improved process, the amount of oil in the paper can be greatly reduced over that previously known by applying it as part of a starch sizing. The oil is uniformly distributed throughout the paper to yield a uniformly oiled paper having great utility for any intermediate or end use operation involving the cutting, punching or trimming of the paper.

Various changes may be made in the treatments set forth herein without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. An on the machine process of making paper for any intermediate or end use application involving the cutting, punching or trimming of the paper which comprises the steps of:

-(a) dispersing a lubricating oil in an aqueous starch sizing consisting of a dispersion of starch in water, to form an oil-in-water emulsion comprising droplets ot the oil amounting to about 1% to 10% of the weight of the emulsion and starch in the amount of at least 1.5% of the weight of the emulsion;

(b) sizing paper at a size press on a paper-making machine with the oil-in-water emulsion at a rate to impregnate the paper with an evenly distributed amount of oil ranging from about 0.2 to 1.5 pounds per ream of paper;

(0) and drying the paper.

2. In the process of making oiled paper on a papermaking machine which involves making a web of paper from chemical wood pulp and then uniformly impregnating the paper with an evenly distributed amount of oil, the improvement which comprises the steps of:

(a) forming an oil-in-water emulsion having as the external phase an aqueous starch sizing consisting of a dispersion of starch in water, wherein the starch makes up about 1.5% to 15% of the weight of the emulsion and having as the internal phase a lubricating oil wherein the oil makes up about 1% to 10% of the weight of the emulsion;

(b) sizing a travelling web of the paper at a size press on a papermaking machine with the oil-in-water emulsion at a rate to provide the paper with an evenly distributed amount of oil ranging from about 0.2 to 1.5 pounds per ream of paper;

(c) and drying the paper.

3. In the process of making oiled paper on a papermaking machine suitable for any intermediate or end use application involving the cutting, punching or trimming of the paper which involves making a web of paper from chemical wood pulp and then uniformly impregnating the web of paper with an evenly distributed amount of oil, the improvement for reducing oil odor of the paper and the tendency of the oiled paper to bleed, and for increasing the opacity of the paper while maintaining its lubricity, which comprises the steps of:

(a) dispersing starch in water to form an aqueous starch sizing;

(b) adding to the aqueous starch sizing an emulsifying agent to aid the subsequent dispersion of an oil in the aqueous starch sizing;

(c) dispersing a lubricating oil in the aqueous starch sizing to form an oil-in-water emulsion comprising droplets of the oil dispersed in the aqueous starch sizing, the amount of starch in the oil-in-water emulsion comprising about 5% to 7% of the weight of the emulsion and the amount. of oil in the emulsion comprising about 3% to 5% of the weight of the emulsion;

(d) applying the oil-in-water emulsion to a traveling web of the paper at a size press on a papermaking machine at a rate to impregnate the paper with an evenly distributed amount of oil ranging from about 0.5 to 1.1 pounds per ream of paper;

(e) and drying the paper.

4. The process of claim 3 wherein following step (e), the following steps are added:

(f) coating the paper web on at least one side with a pigmented coating; and

(g) drying the paper.

References Cited UNITED STATES PATENTS 1,253,397 1/191-8 Lenders 106-210 2,482,917 9/1949 Kaplan 106-213 X 2,666,038 1/1954 Eisen 106-213 X 2,039,279 5/1936 Bouhuys 106-210 3,265,516 8/1966 Triplett et al. 106-213 3,535,155 10/1970 Gathman 117-154 2,819,986 1/ 1958 Edwards et a1. 1117-154 X 1,845,655 2/1932 Fuchs 162-173 3,016,325 1/1962 Pattilloch 162-173 2,602,739 7/1952 Tadema 162-173 S. LEON BASHORE, Primary Examiner F. FREI, Assistant Examiner US. Cl. X.R.. 162-175, 179 

